# Claude Sonnet 4

Claude Sonnet 4 is an AI model released by Anthropic on May 22 2025. At release it scored 30% on BullshitBench v2, 75.4% on GPQA Diamond and 72.7% on SWE-Bench Verified.

## Facts

| Field | Value |
| --- | --- |
| Model | Claude Sonnet 4 |
| Developer | Anthropic |
| Release date | Thursday, May 22 2025 |
| Licensing | Proprietary |

## Benchmark scores published at release

| Benchmark | Score | Source | What it measures |
| --- | --- | --- | --- |
| BullshitBench v2 | 30% | Lab | Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. |
| SWE-Bench Verified | 72.7% | Lab | Real coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. |
| GPQA Diamond | 75.4% | Lab | Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. |

## Questions and answers

### When was Claude Sonnet 4 released?

Claude Sonnet 4 was released by Anthropic on Thursday, May 22 2025.

### Who made Claude Sonnet 4?

Claude Sonnet 4 was built by Anthropic. AI safety company building the Claude family of models. Founded in 2021 by former OpenAI researchers.

### What benchmark scores did Claude Sonnet 4 get?

Claude Sonnet 4 reports 3 tracked benchmark scores — BullshitBench v2: 30%; SWE-Bench Verified: 72.7%; GPQA Diamond: 75.4%. Scores are the figures published at release by Anthropic.

### Is Claude Sonnet 4 open source?

No. Claude Sonnet 4 is a proprietary model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.

### What came before and after Claude Sonnet 4?

Anthropic's previous tracked release was Claude 3.7 Sonnet on Feb 24 2025, 87 days earlier. It was followed by Claude Opus 4 on May 22 2025.


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Canonical page: https://aireleasetracker.com/model/anthropic/claude-sonnet-4
Full dataset: https://aireleasetracker.com/llms-full.txt · JSON: https://aireleasetracker.com/models.json
Source: AI Release Tracker (https://aireleasetracker.com). Benchmark scores are the figures published by the releasing lab at launch.